﻿<blockquote class="extDef">NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
This function returns two orthogonal directions. u[1] is in the direction of ref_direction and u[2] is perpendicular to u[1]. A default value of
(1.0,0.0,0.0) is supplied for ref_direction if the input data is incomplete.</blockquote>

<blockquote class="note">NOTE&nbsp; Function adapted from <strong>build_2axes</strong> defined in ISO 10303-42.</blockquote>

<blockquote class="history">HISTORY&nbsp; New function in IFC1.5</blockquote>